There's an ongoing discussion about this. It seems it has to do with the hitless ARQ modulation change support.
Basically, it's a trade-off. On Jan 13, 2017 10:14 PM, "Mike Hammett" <af...@ics-il.net> wrote: > I love how Gary says they use so much better, newer technology... but > they get worse throughput. *sigh* > > > > ----- > Mike Hammett > Intelligent Computing Solutions <http://www.ics-il.com/> > <https://www.facebook.com/ICSIL> > <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> > <https://www.linkedin.com/company/intelligent-computing-solutions> > <https://twitter.com/ICSIL> > Midwest Internet Exchange <http://www.midwest-ix.com/> > <https://www.facebook.com/mdwestix> > <https://www.linkedin.com/company/midwest-internet-exchange> > <https://twitter.com/mdwestix> > The Brothers WISP <http://www.thebrotherswisp.com/> > <https://www.facebook.com/thebrotherswisp> > > > <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> > ------------------------------ > *From: *"Tim Hardy" <tha...@comsearch.com> > *To: *af@afmug.com > *Sent: *Friday, January 13, 2017 5:54:53 PM > *Subject: *Re: [AFMUG] Our UBNT AF11x experience > > Post 6 here discusses the use of ARQ rather than FEC. > > https://community.ubnt.com/t5/airFiber/AF11x-Capacity/td-p/1737631 > ------------------------------ > *From:* Af <af-boun...@afmug.com> on behalf of George Skorup < > geo...@cbcast.com> > *Sent:* Friday, January 13, 2017 6:41:10 PM > *To:* af@afmug.com > *Subject:* Re: [AFMUG] Our UBNT AF11x experience > > Which I don't understand. Sounds like strong FEC? > > On 1/13/2017 5:36 PM, Ken Hohhof wrote: > > According to Link Planner, PTP820S (IP20S) gets around 243M at 256QAM, > 347M at 2048QAM (350M with header compression). So add that to George’s > Trango/Exalt/SAF list. > > > > *From:* Af [mailto:af-boun...@afmug.com <af-boun...@afmug.com>] *On > Behalf Of *Chris Gustaf > *Sent:* Friday, January 13, 2017 5:20 PM > *To:* af@afmug.com > *Subject:* Re: [AFMUG] Our UBNT AF11x experience > > > > Real usable capacity at Layer 2 Ethernet depends on several variables > besides the modulation level and the regulatory bandwidth. For 1024 QAM > there are 10 bits per symbol so theoretically one would expect to get 400 > Mbps in a 40 MHz channel (10 bits x 40 MHz symbol rate). > > > > To actually make a radio that meets FCC spectrum masks, a reduction of the > symbol rate down to around 35 MHz is required plus filtering, giving a max > of 350 Mbps over the air. > > > > After that, Forward Error Correction (FEC) is required which is typically > around 85-90 % for most microwave radios using LDPC, giving a net > throughput of around 300 to 315 Mbps. > > > > Add header compression at layer 2 which in the worst case for large > packets adds about 2.5 % improvement and you get to around 325 Mbps, which > is what Trango and others get on a single 40 MHz channel with the newest > technology. > > > > Ubiquiti maybe using a lower FEC rate like 75-80% (or a lower symbol rate > if the filtering is not steep enough) and no header compression, which > would give them about 250 Mbps for large packets. > > > > Hope that helps! > > > > Chris Gustaf > > Trango Systems > > > > On Fri, Jan 13, 2017 at 2:39 PM, Mathew Howard <mhoward...@gmail.com> > wrote: > > What other radios will only do 250Mbps (502.4Mbps capacity according to > the data sheet...) on one 40mhz single polarity channel at 256qam? The > other's I've looked at are typically around 300Mbps... > > Not that I'm saying the AF11 is a bad radio, I plan on putting up at least > a few of them this year... but I find it a little funny that they use > 1024qam as a selling point, when it can't do as much throughput at 1024qam > as other radios do at 256qam. > > > > On Fri, Jan 13, 2017 at 4:19 PM, Eric Kuhnke <eric.kuh...@gmail.com> > wrote: > > I think this whole thread can be summed up that there's no magical way to > get around the shannon limit and bps/Hz coding efficiency for a given > channel size and modulation... From the technical perspective of people > who have to really understand the FDX capacity of a new PTP link, the ubnt > marketing department is divorced from reality, it's not 1200 Mbps no matter > how many slick PDFs they publish. > > One 40 MHz channel single polarity at 1024QAM 5/6 code rate is going to be > nearly the same efficiency bps/Hz from many different manufacturers. > Multiply as necessary for dual polarity or for larger channel sizes such as > 60, 80 or 112 MHz. > > > > On Fri, Jan 13, 2017 at 9:38 AM, Faisal Imtiaz <fai...@snappytelecom.net> > wrote: > > FYI... on a "single" 40mhz channel 'dual polarity' (mimo) the expected > throughput on Af11x is 500meg duplex. > > > > Faisal Imtiaz > Snappy Internet & Telecom > 7266 SW 48 Street > Miami, FL 33155 > Tel: 305 663 5518 x 232 <%28305%29%20663-5518> > > Help-desk: (305)663-5518 <%28305%29%20663-5518> Option 2 or Email: > supp...@snappytelecom.net > > > ------------------------------ > > *From: *"Josh Baird" <joshba...@gmail.com> > *To: *af@afmug.com > *Sent: *Friday, January 13, 2017 10:30:10 AM > > > *Subject: *Re: [AFMUG] Our UBNT AF11x experience > > But if I can get 80mhz channels in both polarities (running at > 56Mhz/1024QAM with this radio), I should be able to at least double he > capacity of my PTP-800 link which can do 228Mbps. Right? > > > > On Thu, Jan 12, 2017 at 5:55 PM, Mike Hammett <af...@ics-il.net> wrote: > > At 40 MHz and a single polarity, you're looking at an almost insignificant > increase in throughput. > > Their claim is 1.2 gb+. > Cut that in half as they're advertising the aggregate, so 600 mb+. > That's using both polarities, so now only 300 mb+. > Only I haven't heard of anyone getting much more than 500 in a single > direction (they may certainly exist, I just haven't seen them), so now that > 300 is really only 250. > > > Not much of an upgrade unless you can also get larger channels in both > polarities. > > > > ----- > Mike Hammett > Intelligent Computing Solutions <http://www.ics-il.com/> > > *Midwest Internet Exchange* > > *The Brothers WISP* > > > > <https://www.facebook.com/ICSIL> > ------------------------------ > <https://www.facebook.com/ICSIL> > > *From: *"Josh Baird" <*joshba...@gmail.com*> > *To: **af@afmug.com* > *Sent: *Thursday, January 12, 2017 11:47:42 AM > *Subject: *Re: [AFMUG] Our UBNT AF11x experience > <https://www.facebook.com/ICSIL> > > This PTP800 is only capable of running at 40Mhz (ODU-A) so it can only do > 228Mbps full-duplex. The AF11x should be able to do much more than that, > right? <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > On Thu, Jan 12, 2017 at 12:05 PM, Gino Villarini <*g...@aeronetpr.com*> > wrote: <https://www.facebook.com/ICSIL> > > IIRC, PTP800 is Remec Style, you'll need Remec to N connector adapters > (AF11x is N) <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > What do you expect to achieve with this upgrade? Not much capacity > difference between PTP800 and AF11x, maybe 50-80- mbps more. Only if you > have a xpic license you can double your throughput with the af11x > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > *From: *Af <*af-boun...@afmug.com*> on behalf of Josh Baird < > *joshba...@gmail.com*> > *Reply-To: *"*af@afmug.com*" <*af@afmug.com*> > *Date: *Thursday, January 12, 2017 at 9:12 AM > *To: *"*af@afmug.com*" <*af@afmug.com*> > *Subject: *Re: [AFMUG] Our UBNT AF11x experience > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > Good news - thanks for sharing. <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > Somewhat un-related question: <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > I have a PTP-800 link using these dishes: <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > > *http://www.hol4g.com/AC/product.aspx?number=ANC-VHLP3-11W-RR1&p=237127&sc=0* > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > Do you know if I can re-use these dishes with the AF11x? Do I need > adapters? <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > Josh <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > > > *Gino Villarini* > > President > > Metro Office Park #18 Suite 304 Guaynabo, Puerto Rico 00968 > > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > On Thu, Jan 12, 2017 at 8:07 AM, Gino Villarini <*g...@aeronetpr.com*> > wrote: <https://www.facebook.com/ICSIL> > > Hey all, just dropping by to share our experience with AF11x, we habe been > beta testing the unit since Sept and for the last 3 months, the unit has > been rock solid. <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > We are very happy with its performance, just wished it had a SFP port! > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > This unit replaced a Mimosa B11 unit that we were having some intermitent > throughtput issues, <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > The swap was easy since we reused the Jirous Dishes and only had to add > the af11x adapters to it, <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > The link went live on 9/21/16 and on the first weeks we experienced some > lockups, but after a revised beta fw was applied, all issues went away. > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > For UBNT, please add SFP port and continue the good work towards a af6x > and af18x <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > > > *Gino Villarini* > > President > > Metro Office Park #18 Suite 304 Guaynabo, Puerto Rico 00968 > > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > <https://www.facebook.com/ICSIL> > > > >
